Ex Parte Falk et al

Patent Trial and Appeal Board

Jul 29, 2014

12322897 (P.T.A.B. Jul. 29, 2014)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL
AND APPEAL BOARD
____________

Ex parte ANDREAS FALK, KAREL DE BRABANDERE,
FRANK GREIZER, MATTHIAS VICTOR, TORBEN WESTPAHL,
HENRIK WOLF, and THORSTEN BUELO
__________

Appeal 2012-009120
Application 12/322,8971
Technology Center 2800
____________

Before TERRY J. OWENS, MICHAEL P. COLAIANNI, and
GEORGE C. BEST, Administrative Patent Judges.

COLAIANNI, Administrative Patent Judge.

DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134 the final rejection of claims
1-11, 18, and 19. We have jurisdiction over the appeal pursuant to
35 U.S.C. § 6(b).
We AFFIRM-IN-PART.
Appellants’ invention is directed to a three-phase inverter with a
circuit arrangement having a DC voltage input (2) for least one direct
voltage source (3) and a three-phase alternating voltage output (15) for

1 According to Appellants, the real party in interest is SMA Solar
Technology AG. (App. Br. 1.)
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feeding into a three-phase alternating voltage mains (19) (Spec. 1:4-8;
Figure 1).
Claims 1 and 18 are illustrative:
1. A three-phase inverter with a circuit arrangement
having a DC-voltage input for at least one direct voltage source
and a three-phase alternating voltage output consisting solely of
three output terminals, wherein each output terminal is
associated with a respective phase, the three output terminals
configured to feed into a three-phase alternating voltage mains
when coupled thereto, wherein said inverter comprises a three-
phase bridge circuit as well as an intermediate circuit, wherein
said three-phase inverter is configured to be transformerless,
wherein a neutral conductor of the three-phase alternating
voltage mains is separated from a central point of the
intermediate circuit.
18. A three-phase inverter, comprising:
a DC voltage input with a positive DC potential terminal
and a negative DC potential terminal;
an intermediate circuit connected to the DC voltage
input, and having a midpoint node associated therewith;
a three-phase bridge circuit connected to the intermediate
circuit, and comprising three bridge branches, each associated
with a respective phase; [and]
solely three output terminals coupled to respective output
nodes of the three bridge branches of the three-phase bridge
circuit, so that the positive DC potential terminal and the
negative DC potential terminal are configured to adjust solely
to a conductor to conductor voltage of the three output
terminals.
Appellants appeal the following rejections:
1. Claim 18 is rejected under 35 U.S.C. § 102(b), as unpatentable over
Shekhawat et al. (US 4,670,828, patented June 2, 1987).
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2. Claims 1 and 6 are rejected under 35 U.S.C. § 103(a) as unpatentable
over Shekhawat in view of Nielsen (US 2008/0197706 A1, published
Aug. 21, 2008).

Appellants’ arguments focus solely on independent claims 1 and 18
(App. Br. 3-7).
The following rejections are listed in the Final Office Action and the
Examiner’s Answer (Final Off. Act. 6-15; Ans. 7-16) but are not identified
in the Brief as being grounds of rejection to be reviewed:
3. Claims 2, 3, 8, 10, and 11 are rejected under 35 U.S.C. § 103(a) as
being unpatentable over Shekhawat in view of Nielsen and Chen et al.
(A Novel Inverter-Output Passive Filter for Reducing Both
Differential- and Common-Mode dv/dt at the Motor Terminals in
PWM Drive Systems, 54 IEEE TRANSACTIONS ON INDUS. ELEC. 419-
426 (2007)).
4. Claims 4 and 5 are rejected under 35 U.S.C. § 103(a) as being
unpatentable over Shekhawat in view of Nielsen and Tanaka et al.
(US 6,795,323 B2, patented Sept. 21, 2004).
5. Claim 7 is rejected under 35 U.S.C. § 103(a) as being unpatentable
over Shekhawat in view of Nielsen and Bakran et al. (US 6,930,899
B2, patented Aug. 16, 2005).
6. Claim 9 is rejected under 35 U.S.C. § 103(a) as being unpatentable
over Shekhawat in view of Nielsen and Victor et al. (US
2005/0286281 A1, published Dec. 29, 2005).
7. Claim 19 is rejected under 35 U.S.C. § 103(a) as being unpatentable
over Shekhawat in view of Chen.
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Because the Examiner maintains these rejections and Appellants have not
contested them other than to request the rejections of the pending claims be
withdrawn (App. Br. 7), the dependent claims will stand or fall with our
analysis of the independent claims 1 and 18.
ISSUE
Did the Examiner reversibly err in finding that Shekhawat discloses
“solely three output terminals coupled to respective nodes of the three bridge
branches” as recited in claim 18, and finding that Shekhawat discloses “a
neutral conductor of the three-phase alternating voltage mains is separated
from a central point of the intermediate circuit” as recited in claim 1? We
decide this issue in the negative with regard to claim 18 and we decide in the
affirmative with regard to claim 1.
FINDINGS OF FACT AND ANALYSES
Claim 18: § 102(b)
Appellants argue that Shekhawat fails to disclose that “solely three
output terminals coupled to respective nodes of the three bridge branches” as
recited in claim 18 (App. Br. 3). Appellants contend that Shekhawat
discloses four outputs to the AC load as shown in Shekhawat’s Figures 2
and 3, where the load is connected to the midpoint node N in addition to
junction 13A (App. Br. 4-6). Appellants contend that one of ordinary skill
in the art would understand Shekhawat’s connection of the load at midpoint
N as being an “output” connection to the load (App. Br. 5-6; Reply Br. 1-3).
Appellants contend that page 1, lines 9-13, page 3, lines 31-34, and page 6,
lines 9-13 of the Specification establish the proper claim construction of
“outputs” as being each of the terminals exiting the inverter that couples to
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the mains (Reply Br. 2-3). Appellants do not contest whether Shekhawat
discloses the other limitations of claim 18.
The Examiner finds that Shekhawat’s Figure 1 shows solely three
outputs from the inverter coupled to the respective output nodes of the three
bridge branches of the three-phase bridge circuit (Ans. 5). The Examiner
finds that Shekhawat’s neutral point N is not an output and that only VA, VB,
and VC are outputs. Id.
We begin our analysis by construing the disputed language of claim
18. Claim 18 recites, in relevant part, “solely three output terminals coupled
to respective output nodes of the three bridge branches of the three-phase
bridge circuit.” As shown in Appellants’ Figure 1, the output terminals 11
are coupled to the output nodes of the three bridge branches (i.e., 6, 7, 8) of
the three-phrase bridge circuit. In other words, the disputed limitation in
claim 18 requires that only three output terminals are coupled to respective
output nodes of the three bridge branches. The Specification describes that
the lines leading from the generator 3 is a DC input 2 to the inverter circuitry
and the lines leading away from the inverter circuitry to the low voltage
mains 19 are AC output 11 or 15. In other words, an “output” in the context
of the Specification is a line where AC voltage is lead away from the
inverter toward a load.
With this proper claim construction, we agree with the Examiner that
Shekhawat discloses only three output terminals (i.e., VA, VB, and VC)
coupled to respective output nodes of the bridge branches (i.e., 13a, 13b,
13c). Notably, Appellants do not dispute that VA, VB, and VC are output
terminals coupled to nodes of bridge branches 13a, 13b, and 13c. Rather,
Appellants contend that when the inverter is coupled to a load, the circuit
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includes a fourth output at the node N as shown in Figure 2 or Figure 3 of
Shekhawat. We disagree as Appellants’ argument contradicts the proper
construction of the claim term “output.” The line leading from the load to
node N would be considered an input to the inverter, not an output. Indeed,
even Figure 2 shows that the current flows in the direction of the arrows,
which are directed toward the inverter as an input (Shekhawat, col. 3, ll. 60-
68).
On this record, we affirm the Examiner’s § 102(b) rejection of claim
18 over Shekhawat. For the same reasons, we affirm the Examiner’s
§ 103(a) rejection of claim 19 over Shekhawat in view of Chen.
Claim 1: § 103(a)
Appellants argue that Shekhawat fails to teach or suggest a neutral
conductor of the three-phase alternating voltage mains is separated from a
central point of the intermediate circuit (App. Br. 7). Appellants contend
that Shekhawat’s load 36 is connected to the central point N of the
intermediate circuit C1, C2 (App. Br. 7).
Claim 1 recites that “a neutral conductor of the three-phase alternating
voltage mains [N] is separated from a central point of the intermediate
circuit [M]” (claim 1; Fig 1). Claim 1 requires that the neutral conductor of
the alternating voltage mains is separate from the intermediate circuit M as
shown in Figure 1 (Spec. 6:25-27).
The Examiner finds that Shekhawat describes in Figure 1 that the
central point of the intermediate circuit (N) is separated from the outputs VA,
VB, and VC, which are connected to the alternating voltage mains by the
BDS (bi-directional switches) (Ans. 19).
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However, the Examiner’s finding regarding Shekhawat’s Figure 1
does not address how the neutral conductor of the three-phase alternating
voltage mains N couples to the intermediate circuit (i.e., N in Shekhawat).
As disclosed in Shekhawat, the AC load is not shown in Figure 1, so Figure
1 cannot show how the neutral conductor of the alternating voltage mains
(i.e., the load in Shekhawat) is separated from or coupled to the intermediate
circuit. Only in Figure 3 of Shekhawat is it disclosed that the AC load is
coupled so that the neutral conductor from the AC load 36 is coupled to the
intermediate circuit (i.e., N) in Shekhawat as argue by Appellants.
Because the Examiner has not satisfied the initial burden of
establishing a prima facie case of obviousness, we reverse the Examiner’s
§ 103 rejection of claim 1 and the § 103 rejections of dependent claims 2-11.
The Examiner does not rely on any of the secondary references to cure the
argued deficiency with respect to Shekhawat.
DECISION
The Examiner’s decision is affirmed-in-part.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).
ORDER
AFFIRMED-IN-PART

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